Azaborabutadienes: Synthesis by Metal-Free Carboboration of Nitriles and Utility as Building Blocks for B,N-Heterocycles

• Main Authors: Kong, Lingbing, Lu, Wei, Li, Yongxin, Ganguly, Rakesh, Kinjo, Rei
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2017
• Subjects: Carboboration; Azaborabutadiene
• Online Access: https://hdl.handle.net/10356/85149; http://hdl.handle.net/10220/43658
• Institution: Nanyang Technological University

Metal-free regioselective carboboration of arylnitriles with L2PhB: (1: L=oxazol-2-ylidene) catalyzed by Et3B afforded the unprecedented acyclic 2-aza-4-borabutadienes 2, thus demonstrating a new strategy to construct a B,C,N-mixed π-system involving B=C and C=N bonds. Thermal isomerization of 2 gave C-borylimines (3), and diverse reactivity of 2 a towards several substrates, such as H+, F+, O2, S, Se, and isonitriles, allowed construction of boron-containing heterocycles with various ring sizes, thus illustrating the utility of 2 as a synthetic building block.